


Science Blues

by museaway



Category: Star Trek: Alternate Original Series (Movies)
Genre: Bodyswap, Convenient regulations, Drinking bourbon (and lots of it), Drunken Confessions, Dubious Science, Getting hit on by your best friend because he thinks you're someone else, M/M, Misunderstandings, Sass, Spock playing matchmaker, Trying to talk like a hobgoblin, so much sass
Language: English
Status: Completed
Published: 2014-03-02
Updated: 2014-03-02
Packaged: 2018-01-14 06:09:56
Rating: Teen And Up Audiences
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 14,770
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/1255762
Author URL: https://archiveofourown.org/users/museaway/pseuds/museaway
Summary: <blockquote class="userstuff">
              <p>"Illogical" wasn't a word that ever should have come out of Leonard McCoy's mouth, so when it happened, he looked up through a narrowed pair of Vulcan eyes and into his own face.</p>
            </blockquote>





	Science Blues

**Author's Note:**

  * For [jouissant](https://archiveofourown.org/users/jouissant/gifts).



> Thanks to my mom for acting as science advisor and pointing me toward bufotoxins, which comprise the bulk of the "science" in this story. She also named the planet (she was very excited about this). _A huge thanks to_ [Middletone](http://middletone.co.vu) for consulting on McCoy's breakfast and lunch choices; to the creator of [this amazing gifset](http://www.museaway.com/post/75612662691/misspistachiocraver-bonesys-star-trek-au), which gave me the idea to do this story in the first place (though this version is obviously K/S); and to [searchingforspock](http://searchingforspock.tumblr.com), [thisislogical](http://thisislogical.tumblr.com), [hipposandeggshells](http://hipposandeggshells.tumblr.com), and [CanneDeBonbon](http://cannedebonbon.tumblr.com) for checking this over so thoroughly. You guys are the best. 
> 
> _For_ [jouissant](http://archiveofourown.org/users/jouissant), who was so excited about this idea that she enthusiastically brainstormed with me for a day on Livejournal. I hope you love this. Happy (early) birthday!

"Illogical" wasn't a word that ever should have come out of Leonard McCoy's mouth, so when it happened, he looked up through a narrowed pair of Vulcan eyes and into his own face.

"Oh, for the love of..." he muttered as he watched his own face look back at him with a neutral expression and lift one eyebrow.

"Dr. McCoy," said Dr. McCoy, who, despite the southern accent, sounded suspiciously Vulcan. "It appears we have switched bodies."

"You don't say," replied Spock, who, despite the smooth Vulcan cadence, sounded suspiciously sarcastic. "How did this happen?"

"I do not know."

They both cast their eyes to the flower between them. It looked innocent enough. It was certainly nothing to write home about, a sort-of ugly yellow bloom with a dark center which Spock-who-was-now-McCoy had been scanning with a tricorder. The flower possessed no remarkable qualities (nothing discernable, at least, though psychotropic plants often fool technology). It wasn't in their plant database, so Spock asked McCoy to hold the bloom still while he took additional readings and measurements. Spock had just been commenting on the flower's pollen structure when he sneezed. McCoy sneezed. Spock commented that he had no known allergies, thus for him to sneeze from inhaling this plant's pollen was illogical.

It had come out of McCoy's mouth.

They both glanced over their shoulders, to where the rest of the away team ambled in groups of two and three. A couple of red shirts flanked the captain, who, as he often did, was touching every rock and tree he could get his hands on.

"We must inform him of the situation," Spock said, starting to get up.

"Now, hold on just a minute," McCoy snapped, and Spock returned to his kneeling position. "I'm not about to be relieved of duty because of some...plant. There has to be a way to reverse this."

"After I speak with the captain, I will beam back to the ship and consult the ship's computer," Spock said.

"We'll both be put on medical leave!" McCoy hissed. "Are you familiar with medical regulation 515?"

"Crew members who experience a reaction to alien flora and/or fauna are required to terminate their duty shift and report to sickbay immediately for mandatory quarantine," Spock recited.

"And we'll be restricted to sickbay until further notice. We won't be allowed back down to study the plant—hell, we won't be allowed out of medbay. Do you actually trust your scientists to discover what happened as well as you can? They're as green as they come. Don't tell me you forgot that Ensign what's-her-name got herself stabbed by barbs just last week, not ten minutes after you issued the caution memo. I had to pull them out myself. You trust _her_ with this?"

He watched Spock mull this over, pressing his lips into a line. It was surreal to look into his own face, so devoid of expression.

"No," Spock said finally.

"Good," McCoy agreed. "We're both men of science. I'm sure with a couple hours of research, we can get to the bottom of this and reverse it. No one needs to know."

"While I appreciate your enthusiasm," Spock said dryly, "I have never encountered a substance capable of life-energy transfer."

"Meaning?"

"Despite our combined scientific expertise, there is no guarantee that we will be able to discover a method of reversing the plant's effects."

"You're just a ray of sunshine."

"I am attempting to be realistic," Spock said stiffly. "We must accept the possibility that there may be no remedy."

"Dammit, man, I'm not going to die with pointed ears," McCoy whispered. "If Jim can survive radiation poisoning, we can find a way to switch us back to our own bodies."

"If you recall," Spock said, narrowing his eyes, "the captain did not survive."

McCoy glared at him and exhaled slowly through clenched teeth. Spock stared back and finally blinked, his eyes flicking to the tricorder screen in McCoy's hand.

"We are scheduled to be in orbit around Silvis VII for three standard days," Spock continued. "That should provide ample time to research the plant and for us to interview the natives. Perhaps they have information which would prove useful."

"And we just have to make sure that no other crew members approach this flower while we're here," McCoy said.

"What do you suggest?" Spock asked.

"You're the science officer. Can't you...declare this area unsafe?"

"I must release a likeness of the flower, so it can be avoided."

"And just how do you plan to explain why this particular flower is dangerous? It's not part of any documentation. Sure wasn't in the briefing I read."

"Yet you find declaring this entire area a hazard to be a logical step?"

"Dammit," McCoy said. "Just think of something."

"I maintain that we should tell Jim," Spock said finally. "He is adept at obfuscation."

"No," McCoy said. "I don't want to bring him in on this unless we have to."

"I fail to understand why we must not inform him," Spock said and scowled. "As the captain, he must be made aware. I am his first officer. It is my duty to apprise him of the situation."

"You tell him," McCoy said, and he found it oddly simple to lift an eyebrow as he did so, "and he'll tell everyone on the damned surface once he's done laughing. Kid doesn't have a lick of sense when it comes to propriety."

"I have surmised as much," Spock agreed.

"It's probably best to avoid him, just until we have this sorted out. It's not just the landing party we have to be afraid of finding out. You know he'll say something to Scotty, and if the Roylan finds out...well, you know what they say: loose lips sink ships."

"Is Mr. Keenser experiencing a problem with his orbicularis orsis muscle?"

"My god, man. How many years have you lived around humans?"

"Thirty-one," Spock informed him crisply. When McCoy frowned, he added, "My mother was human, as I am certain you recall."

Sighing, McCoy waved away the comment. "So we're in agreement," he said. "We don't speak of this to anyone, and we steer clear of Jim, just until we find a solution."

"Yes," Spock said, though the declaration appeared to pain him. McCoy shivered.

"Are you cold?" he asked, rubbing his arms. "I'm suddenly freezing."

Spock smirked.

***

Avoiding Jim on planet was damned near impossible, McCoy grumbled to himself. Twice, McCoy had sent a lieutenant to bother him about something innocuous when Jim looked like he might approach. They were in the middle of taking a sample of the flower's leaves, petals, pollen, and roots when Jim walked up and knelt between them. He clapped McCoy-who-was-really-Spock on the back. Spock's eyes widened.

"Never seen you two look so close before," Jim said brightly. "Find anything interesting, Bones?"

McCoy opened his mouth to answer but remembered in time and bit down. He caught Spock's eyes and nodded minutely.

"Yes, Captain," Spock replied in McCoy's southern drawl, and McCoy entertained a vision of him on a veranda sipping a mint julep. He cleared his throat.

"Oh, I'm 'captain' today, huh?" Jim asked with a sunny grin. "What's so interesting about this flower?" He reached a hand toward it, and both McCoy and Spock lurched forward to stop him. McCoy locked a hand around Jim's wrist, and Jim looked up at him, startled. Vulcan strength, McCoy realized too late. He immediately released Jim's arm and watched him rub the reddened skin.

"Jim," Spock said gently and held out his hands. "Let me see."

"It's fine, Bones," Jim said quietly, but he let Spock examine his wrist.

"Merely a bruise," Spock determined, shooting McCoy a narrow look. "Clearly, Mr. Spock, you do not realize your own strength."

McCoy felt his face grow warm. "I'm sorry," he offered. Jim shot him a strange look but got to his feet. The other two followed.

"Spock, is your team about done collecting samples? Looks like the sun is going to set, and I'm getting hungry. I'd like to start beaming the team members back to the ship. Want to grab dinner in a bit?"

"We are nearly through, but I request permission to remain on surface, Captain," Spock said, then closed his mouth quickly as Jim's face contorted. Spock glanced to McCoy and widened his eyes.

"Yes," McCoy jumped in, folding his arms behind his back the way he'd seen Spock do a hundred times. He straightened his back. "Dr. McCoy agreed to help me analyze samples. He's correct that we require additional time."

"Since when do _you_ help with samples?" Jim said, frowning as he turned to look at Spock.

"Dr. McCoy is a _gifted_ scientist," McCoy replied and smirked at Spock, who raised a human eyebrow.

"Okay," Jim said. "How much time are we talking? Should I just grab dinner on my own?"

"That would be best," Spock replied. He cleared his throat and folded his arms over his chest. "You are looking rather thin, Jim."

"Rather thin…" Jim repeated. He laughed and smacked Spock's back again. "Well...keep at it, then. I'll see you in the morning for breakfast."

He shook his head and looked at McCoy. His face softened slightly, into an expression McCoy didn't recognize. Jim took a step closer to him.

"See you later?" he asked quietly. McCoy nodded and was relieved when Jim beamed and trotted off toward the rest of the away team.

"Do you think an hour's enough time?" McCoy asked as soon as Jim was out of earshot.

"It is a start," Spock replied and began to process the root sample.

***

Forty minutes of scans revealed the flower's DNA sequence and cell structure, that it contained high amounts of bufotoxins, and was apparently the only one within a one-mile radius. Spock's portable scanner showed no traces of such a chemical profile anywhere in the immediate area. He suppressed a sigh and switched off his tricorder, pursing his lips.

"Let's walk into town," McCoy suggested. "It's their planet. They probably know something. We should've gone there in the first place."

"There is not time to speak with the village elders tonight," Spock argued, clasping his arms behind his back. The surface was dark. McCoy had found an emergency lantern in his med kit, and they used it to illuminate the small area surrounding the flower. "They are a diurnal culture, and the sun has already set."

"You're telling me," McCoy answered through chattering teeth. He had a thermal blanket draped over his shoulders, but it was clearly ineffective. "This is an emergency. I don't see why we can't bang on their door."

"They have likely taken their evening meal," Spock said, feeling quite warm in a fully human body. "From what I understand of this culture, they engage in worship for an extended period every evening following that meal, then take their rest. If we expect their assistance, it would not be wise for us to interrupt their ritual."

"I guess not," McCoy admitted.

"It is possible the flower is sacred to them and that we have violated a rule of their culture merely by touching it," Spock extrapolated. "Plants capable of less extraordinary results are revered in many mythologies."

"How the hell are we supposed to get any answers out of them?"

"We must inquire as to their mythology," Spock said.

"And hope something they say is useful?" McCoy exclaimed. He threw up a hand, then tucked it under his armpit. Spock grimaced. "How the hell do you not freeze your ass of on away missions?"

"I find your body sweats unnecessarily," Spock said and sniffed. "It is decidedly unpleasant."

When McCoy's shaking became exaggerated to the point where Spock almost rolled his eyes, he agreed they should return to the ship.

"I will stay in my laboratory tonight," he said, "and continue to run scans."

"What on Earth do you expect to find that we haven't already tested for?"

"The tricorder is designed to gather a basic profile only," Spock said. "It does not cross reference this plant against the ship's entire database for a DNA match, nor is it capable of searching for similar known plants and compounds."

"So I guess that means I'll get to spend the evening with you in your lab," McCoy huffed. "Just what I had in mind."

"I suppose it will be necessary for you to be there," Spock admitted.

"What if we aren't switched back by tomorrow morning?" McCoy asked. "Am I supposed to report to the bridge, pretend to know what you see in that scanner of yours?"

"That would not be ethical," Spock said, considering. "Nor would it be ethical for me to perform your duties as a physician."

"So we both call in sick, hide out in the lab?"

"We have both spent the evening in each other's company," Spock said slowly. "It is not implausible that we contracted the same illness at some point."

"M'Benga and Chapel can handle medbay."

"Mr. Chekov is proficient with the tasks of my station," Spock admits. "He will be an adequate replacement."

" _If_ it comes to that," McCoy added. "I'm sure we'll figure this out tonight."

***

It was well past midnight, a dozen experiments and no answers later. Spock slumped heavily against the turbolift wall, his eyes falling closed, and yawned ungracefully. McCoy was still wide awake and appeared warmer now that they were back on the ship, but his motions were still jittery. They hadn't eaten dinner, and Spock's stomach growled. It was an unfamiliar sensation. He would eat when he returned to his—McCoy's, he corrected himself—quarters. He hoped that McCoy had a decent selection of vegetarian options in his replicator. Spock supposed this must be the case, since McCoy was always reminding Jim to add more vegetables to his diet plan.

 _Jim_.

Spock reached out a hand and stalled the turbolift.

"Doctor," Spock said carefully, uncertain where to begin, "you are aware that Jim and I share...a bathroom."

"We all share bathrooms, Spock."

"Ah," Spock said. "I meant to inform you that Jim does not always knock."

"I'll be sure not to stand around in my birthday suit," McCoy answered. "Um... _your_ birthday suit," he corrected and rubbed his hands together. Spock's were pleasantly warm, but his stomach twisted nervously. He cleared his throat.

"Although we have no formal arrangement," he continued, "it would also be prudent for me to tell you—"

"Spock," McCoy interrupted and slapped Spock's hand away from the turbolift controls. It rumbled to life again beneath their feet. "I just want a good night's rest. Okay? You can fill me in on Jim's lack of manners over breakfast."

"I am not speaking about his manners," Spock went on. "For the past twenty-six nights, Jim has been sleeping—"

"Look," McCoy said sharply. "I lived with the kid for a couple years. Nothing and no _one_ he does is going to surprise me. Now I'm going to grab a shower, something to eat, and try to warm the hell up."

Spock felt anger flare up in him, but he was tired, and it simply drained as fast as it had come. McCoy had made up his mind; there was no logic in continuing to argue.

"As you wish," Spock muttered and watched the light sweep up the turbolift wall as they passed each floor.

They parted at the first turn in the corridor, Spock turning right toward McCoy's cabin, and McCoy heading left toward Spock's. Spock felt a yearning for his own things: his bed, his chess set, his meditation robes. They were merely material possessions, he reminded himself, and to yearn for them when he could not have them was illogical. He could, he _must_ bear this for one night.

McCoy's quarters were comfortable and notably cleaner than Jim's (which Spock found resembled his roommate's half of his first-year dormitory in San Francisco). This room smelled faintly of leather, wholly different from how Spock's room smelled, and nothing like the medical bay. It was sparse in terms of decor: a knitted throw draped over the sofa, a stack of pads neatly arranged on the desk. Beside the bed was a small silver frame holding a holo of a young girl, perhaps eight years old. Spock knew that McCoy had a daughter but had never seen a likeness of her before. He noted her eyes were similar in shape to McCoy's and found himself ashamed that he had never asked about her.

After tea and a light bowl of soup, he discovered the human gag reflex when attempting to brush his teeth with McCoy's toothbrush. His reaction was irrational, considering he currently occupied McCoy's body, but each time he brought the cleaning instrument to his mouth, he felt a wave of nausea sweet from his stomach to his throat. He threw the toothbrush away and replicated a new one, satisfied when the unused bristles contacted his teeth and gums. He brushed methodically, then retreated to the bedroom to fetch sleeping clothes. He was exceedingly comfortable and chose a light pair of cotton pants with a drawstring waist, settling onto the floor for meditation.

With a human's neural pathways, he found it difficult to concentrate. His thoughts centered on Jim, on the dishonesty he felt concealing what had happened from him. Surely if the situation were reversed, Jim would confide in him. Spock was troubled by his own deception, that he had agreed not to speak with Jim, that he had agreed to avoid him. He did not wish to. He glanced at the comm, McCoy's comm, on the nightstand.

Though he was warm when he crawled into the bed, having ordered fresh sheets and a pillow, he was lonely and did not suppress the shiver when he hugged his own ribcage and closed his eyes.

***

Once he reached Spock's quarters, McCoy was grateful for the blast of heat that met him when the door slid open. He ordered the temperature up an additional five degrees and went to shower, shaking under the sonics and retreating for the heat of the bedroom as soon as he deemed himself clean enough. He didn't bother brushing his teeth, replicated a bowl of stew and a mug of tea and shook beneath a blanket.

At one point, he heard the sonics start up again. Jim must be grabbing a shower. McCoy jumped a little when the bathroom door opened and Jim poked his head inside, but he remembered what Spock had told him in the turbolift and nodded at him. He wondered if Spock would make that motion and decided it was best to stay very still.

"Okay if I come in?"

McCoy nodded. His eyes widened when Jim stepped into full view in just a towel slung low around his hips. Spock was generally antsy in sickbay when it came to nudity, so McCoy was surprised that Jim would dress like this (or not) around him.

"You're still cold?" Jim asked, noting McCoy's cocoon. "It's like an oven in here."

He crossed the room until he stood at the side of the bed, looking down at McCoy. His chest was pink from the sonics, and McCoy was irritated to find that Spock's body was reacting to Jim's proximity. He scowled. Crazy mixed-up Vulcan physiology.

"Did you forget your thermal today?" Jim asked.

"No," McCoy answered. He swallowed hard when Jim sat next to him.

"You were driving me crazy on the surface," Jim said in a low voice. He slid a hand onto McCoy's thigh— _Spock's_ thigh. "Have I ever told you how hot you look when you're in science mode?"

McCoy was frozen stiff, his mouth dropped open when Jim squeezed his leg. Spock and Jim? Since when? Is that what Spock was trying to tell him in the lift? Damn his impatience; he should have let him finish. Spock's outburst on the planet made sense too, in retrospect, when McCoy had grabbed Jim's wrist too roughly. And now he understood the strange look Jim had given him before he walked away. It was the same look Jim was giving him now, hopeful and expectant, and a little uncertain. He'd never seen anything like it on Jim's face, not even when he would talk about Gary. How long had this been going on?

"I'm sick," he blurted, scrambling to find his inner Vulcan. "You shouldn't...it would be wise for you to maintain...a distance."

"Unless you caught something on planet today, I'm pretty sure I have whatever germs you've been carrying around, especially after last night."

"That's...logical," McCoy managed, which was the wrong thing to say, because Jim looked encouraged.

"Speaking of last night, you up for another round?" Jim slid his hand further up McCoy's thigh, to his groin, and pressed. There was no way in hell that Leonard McCoy was having sex with Jim Kirk, no matter whose body he was currently occupying. He did jerk away this time, but he instantly regretted it when Jim's face fell.

"Sorry," Jim said, pulling his hand back into a loose fist between them.

"I—" What the hell would Spock say? "It's fine," he offered.

"I get it," Jim said. "You're tired. I guess that means no chess tonight either?"

"Maybe tomorrow?" McCoy offered.

"Think I'll sleep in my room tonight, let you have the extra space."

He leaned forward and kissed McCoy, just long enough that McCoy realized there was feeling behind it. No, it wasn't just a realization—he actually _felt_ Jim's emotions, just for a moment. He shut his eyes but didn't kiss back. When he looked again, Jim's eyebrows were furrowed.

"Okay," he said quietly. "Goodnight."

"G'night, Jim."

There was a flicker on Jim's face, but he stood and smiled his way out of the room, lingering in the doorframe for a moment before his fingers were the only things visible, curled around the edge. They disappeared behind him. The bathroom door closed, and McCoy rolled onto his back.

"Well, shit," he cursed the ceiling.

***

McCoy was awake at 0430 and ready to start the day, but the ship was quiet around him except for the engines humming. He'd learned in medical school that Vulcans don't require the same amount of sleep as humans, but he had always blamed Spock's efficiency on stubbornness. He was surprised by how rested he felt, rolling his neck side to side and stretching his arms over his head. He was finally warm, even his toes, which he'd already declared casualties of frostbite. He stretched them and got out of bed, dressed, and settled at the computer.

If he was going to be awake at this hour, he might as well put his time to use. He was chief science officer on a Federation starship. That afforded him high levels of clearance in Starfleet's database, maybe even what had been salvaged from the VSA.

The VSA. He wondered if the other Spock, the old one who lived out on the colony, had ever encountered a plant like this? He reasoned that it wouldn't get them into any official trouble if he contacted the colony. The other Spock wasn't affiliated with Starfleet any longer, so confiding in him shouldn't compromise either his or Spock's career.

"Computer," he said. "What time is it on New Vulcan?"

"Current time on New Vulcan is 1945."

"Damn," McCoy swore. That was almost midnight on the colony. He scratched his head and wondered if he should call anyway, remembering how awake he'd felt the night before. The other Spock probably didn't sleep much either, but McCoy wasn't going to be the one to piss him off.

After staring at the blank monitor screen for ten minutes, he headed for the recreation deck, intent on running to kill time until the younger Spock woke up. It was early enough that he chanced it, unlikely to run into any other crew members. The ones who were awake were on duty. And if he did happen upon anyone, he reasoned that most of the crew was intimidated by Spock, so it was a non issue. He'd just raise an eyebrow, maybe two, and be on his way.

Spock was in excellent shape, McCoy had to admit, as he completed his third mile on the simulated track. He'd barely started to breathe heavily, and it was interesting to note that Spock's body hardly sweated. In med school, McCoy had heard full-blooded Vulcans don't sweat at all to conserve water, so McCoy marked Spock's unique physiology down to being half human. His own shirt would've been soaked by now; Spock could practically attend a diplomatic function in this one.

He ran an additional two miles before stopping to stretch. It had to be close to 0600 by now. Surely Spock would be awake? McCoy showered only long enough to ensure he wasn't rank and headed for his own quarters, frowning when the scanner didn't recognize him. He pounded on the door, checking the corridor to ensure he was alone. Spock answered the door, looking like a bleary-eyed human.

"Oh, don't tell me you're tired," McCoy said and pushed past him into the room. Spock yawned and covered his mouth.

"I find," he said behind his hand, "that I require significantly more sleep as a human."

"Yeah, well, I've been awake for two hours," McCoy griped. "And Jim kissed me last night."

Spock looked sheepish, clasping his hands before him. "I attempted to inform you of our...arrangement."

"You're sleeping with him," McCoy accused.

"Yes," Spock said. "It is not an ideal situation."

"I don't need any specifics," McCoy said. "I think he bought that I was tired last night."

"I presume he slept in his own quarters?"

"I'm not cuddling your boyfriend on your behalf," McCoy snapped.

"He is not..." Spock began. He lowered his head. "We have no formal understanding."

"Oh, even better. You know that you should both come in for medical workups."

"I do not believe he intended for you to know."

"Well, he usually doesn't." McCoy noticed the way Spock swallowed and turned away.

That hadn't come out right; Jim didn't usually inform McCoy of his affairs because they were short lived. This was different, and McCoy had a feeling Jim hadn't told him _because_ it was different, but he didn't know how to convey that to Spock. And dammit, he wasn't a relationship counselor. He changed the subject.

"Do you think that old version of you would be any help in figuring out what happened to us?"

"I considered contacting him," Spock said. "It is possible that his _Enterprise_ encountered a similar set of circumstances."

As it turns out, his _Enterprise_ had, only it had been due to ancient machinery, and Jim had been the one affected.

"Are you aware of an organic compound which causes life-energy transfer? Dr. McCoy and I believe that our situation was caused by a flower we touched on Silvis VII."

"I am unfamiliar with a plant capable of such a feat," the elder Spock said with two raised eyebrows, which McCoy interpreted to mean "oh, shit" in Vulcan.

"We are grateful for your assistance," Spock told him.

"Damn," McCoy swore as the call disconnected.

"That was unfortunate," Spock agreed and yawned.

"Oh, go back to sleep, you lightweight," McCoy chided him, heading for the door. "I'm going to get something to eat. I'm starving. Does your replicator make sausage gravy?"

"I would caution you to avoid rich foods, unless you wish to experience stomach upset."

"I have plenty of hypos for that," McCoy told him.

"Ah," Spock said, and the right side of his mouth lifted. "Should I remind you that I am the one in possession of the aforementioned hyposprays?"

"You wouldn't."

"My breakfast typically consists of a light broth," Spock said, "and a loaf of replicated _kreyla_."

"Fine," McCoy said, crossing his arms. "In that case, I expect you to eat a traditional Southern breakfast: fried eggs, bacon and sausage, fried okra. Heap of grits. If you're still hungry, waffles with whipped cream and strawberries. A man can't survive on broth alone."

"I would prefer not to—"

"Now, Spock," McCoy said. "What's good for the goose..."

Spock looked at him through narrowed eyes but pressed his mouth into a line and nodded.

"Very well," he said, "although I fail to see what Terran fowl has to do with the subject."

"Funny. Oh, and don't forget the coffee: at least two cups, or you'll get a headache. Just don't tell Jim. I've got him thinking I only drink a cup a day. Trying to get him to cut back."

"I have observed that he has a strong dependency on caffeine."

"So would you, if you had insomnia like he does."

"I have not noticed that the captain has problems sleeping," Spock said through a frown. "He has slept an average of seven point three eight hours for the past twenty-six nights."

"He's doing regular sleepovers now?" McCoy said, raising an eyebrow. _Damn_.

"Is that unusual?" Spock asked, cocking his head.

"You're in uncharted territory."

"I see. I gathered from my relationship with Lt. Uhura that sharing a bed is a custom practiced by many Terrans."

"Oh, it is," McCoy assured him. "Just not one Jim's ever subscribed to. Glad to see the kid's growing up."

"Would you say it is positive that he engages in this behavior with me?"

"I'd say it's Earth shattering." McCoy took a chance and set a hand on Spock's shoulder. "Go back to sleep. You look like hell."

Spock raised one of McCoy's eyebrows. "Your hair is untidy."

McCoy dismissed him with a wave of his hand and left for Spock's quarters. His heart rate had come down enough since running that his body was beginning to cool, and he was uncomfortable again.

He sent a message to Jim that he (well, _Spock_ ) would not be able to report for alpha shift and buried himself back underneath the covers. He closed his eyes and didn't sleep, but it was surprisingly easy to slip into a meditative state. He stayed there, content (and he was never admitting that to anyone, _ever_ ) until the connecting door slid open.

"Hey," Jim said, coming to sit on the edge of the bed. He placed a hand on McCoy's forehead and stroked it gently. McCoy stayed absolutely still, fighting the urge to grimace. He could feel Jim's concern. "Bones is sick too. Do you think it's something you picked up on planet?"

"Unlikely," McCoy lied and pulled the covers up higher. "No one else has reported sick."

"True. Here," Jim said, going to the closet and coming back with another blanket. He spread it over McCoy's legs and smoothed a hand over them. "Can I get you anything?"

McCoy shook his head.

"Okay," Jim said. "Try to get some sleep. I've got to head up for my shift. Chekov's got your station covered. It's not like anything will be going on today except a meeting with the elders, and Uhura is coming with me."

"Captain," McCoy said, trying to recall what the damned briefing had said about their schedule on Silvis VII. "I thought that meeting was two days from now."

"It was," Jim admitted. "But it got moved up. They just alerted me a little bit ago. I didn't want to bother you about it since I knew you weren't feeling well."

Hesitantly, he leaned forward and kissed McCoy on the forehead. When he sat back, he grinned.

"If you need anything, comm me?"

"You'd leave the bridge for me?" McCoy asked, raising an eyebrow. It was irritating how natural that seemed. Jim, bless him, blushed. McCoy would've rolled his eyes if he'd been in his own body.

"I'll check on you at lunch," Jim said, touched two fingers to McCoy's hand, and left.

Well, this was just great. Now they had to work out a way to get down to the surface that wasn't incongruous with their dual sick day. As soon as he was certain the bathroom door had closed, he commed Spock, who answered on the second ring.

"Dr. McCoy," he said.

"Dammit, man," McCoy muttered. "Say 'McCoy here.' You make me sound like a robot."

"You hardly sound Vulcan," Spock huffed in reply. "Was there a purpose to your communication?"

"No, I just called to compare our speech patterns. Of course there's a purpose. The meeting with the elders got pushed to today."

"That is unfortunate."

"Unfortunate? This could mean our careers."

"My word choice is not ideal," Spock corrected. "My cognitive abilities seem to be reduced. You must accompany the away team."

"Jim was just here not two minutes ago. I don't think he'll buy spontaneous recovery."

"He would not be surprised if I insisted on accompanying him to meet with the elders, despite an illness."

"What do you want me to do, show up in the transporter room?"

***

McCoy entered the transporter room with a scowl as he tried to adjust the mission belt on his hips. He'd added a half inch to his girth with the two undershirts he had beneath his tunic, and the belt wouldn't fasten. He almost had the stupid thing buckled when the door swooshed open behind him and Jim strode in.

"Spock!" he exclaimed. "You should be in bed."

"Negative," McCoy replied, trying to recall the various ways Spock had of telling Jim 'no.' "I'm going to accompany you to the surface." Did Spock use contractions? Hell.

"I knew I shouldn't have told you about the meeting change," Jim said, rubbing his forehead. He took the belt from McCoy's hands and fastened it with a snap. Jim's hands lingered on his waist for a moment before Jim dropped them to his sides. "But I'm glad you'll be coming with me. You sure you feel up to it?"

"I feel fine," McCoy answered.

"I'd order you to stay on board," Jim said, "but I have a feeling you'd beam down after me anyway. Shall we?"

He chuckled and nodded to the transporter pad where two members of the security team already waited. McCoy followed him up the steps.

"Guess I should comm Uhura," Jim said, "tell her she doesn't need to come with us."

"It might be worth bringing her along," McCoy said quickly, "in case the universal translator fails."

"Logical," Jim teased and lightly elbowed him in the ribs. They waited for Uhura to arrive, which she did a minute later, adjusting her own belt. She looked at McCoy with a raised eyebrow of her own.

"Thought you were sick in bed," she said.

"I recovered."

She glanced between McCoy and Jim and climbed onto the platform. Jim nodded at the lieutenant manning the controls.

"Energize."

Despite the sun being already high above the horizon and the planet warm, McCoy shook as soon as he re-materialized on Silvis VII. Uhura pointed in the direction of the village and started off with their security detail. They were several paces ahead when Jim paused and turned to McCoy. He held out a hand with two fingers extended.

"Really glad you came," he said and looked at McCoy expectantly. McCoy glanced at his fingers for a few seconds, then back at Jim's face, which was suddenly tight. He belatedly realized he was supposed to do something in return, but he had no idea what. Jim curled his fingers into his palm and smiled broadly, but it was the smile McCoy often saw him flash during interviews. Jim shook his head and picked up his pace a step.

"Uhura's going to beat us there at this speed," he exclaimed and trotted off after her.

***

Spock paced McCoy's cabin nervously, awaiting a message. He was aware that to pace was unproductive. It provided no mental clarity and did not even serve to calm him. It merely wasted energy and made him feel more anxious, which was an emotion he did not care for. He frowned and squeezed his hands together, glancing at the comm again. He was looking at it every few seconds, but he found himself unable to perform the calculation to determine the precise length of time which passed between glances.

McCoy had been on the surface for several hours—Spock had lost track of how many. If there was something to be learned from the inhabitants, surely McCoy had learned it by now? Spock had composed several questions for McCoy to ask. The doctor was not a diplomat, but he was an intelligent man.

When the comm finally lit up with a message, he scrambled for it, only to discover the message was from Jim. His heart sped up—and how odd to feel his heart beat toward the center of his chest. _The message is for Dr. McCoy_ , he reminded himself, and read it.

>> need to talk. your quarters after shift

Spock experienced a flicker of jealousy, but he chastised himself for it. It was not logical that he should feel jealousy toward McCoy. He and Jim were close friends, had known one another longer than Spock had known Jim. It followed that Jim would continue to confide in McCoy. Perhaps the issue was medical in nature. No, Spock told himself. If that were the case, Jim would not have sent a personal communication.

He sighed and held the comm in both hands, debating what he should say in reply. His body thrilled at the idea of Jim coming to see him. Although he tried to suppress the flurry of emotions, he found that he could not. He attempted to shield his emotional brain, but nothing happened when he did so. Fascinating. He frowned and entered a reply.

>> Of course. I will be here.

He was certain he'd heard McCoy use similar phrasing. He sent the message and returned the comm to the table.

Another hour passed, and his head began to ache steadily at the temples and behind his eyes. What had McCoy said about coffee? Spock found his memory lacking. He had always been able to recall past conversations in perfect detail, but his exchange with McCoy was fuzzy. He remembered that it focused around Jim's caffeine consumption. Of course, Spock remembered. McCoy's body also required it.

He went to the replicator and ordered one cup of coffee, using McCoy's preset. It contained no sweetener or cream. He blew on the surface and inhaled. It smelled like the coffee which Spock sometimes prepared for Jim, and he noted that McCoy's body reacted positively to the aroma. He felt the corners of his mouth lift, and he brought the mug to his lips.

Spock held the scalding liquid in his mouth for all of three seconds before he went into the fresher and spit it out, brushing his teeth furiously to remove the taste. Why would someone elect to consume such a beverage? Why did it taste nothing like it smelled? The smell was pleasant, but the drink itself was bitter. He scrubbed his tongue, then ordered a cup of tea instead. He reasoned he would need to consume at least six cups in order to reach the level of caffeine which McCoy's body required. At least Spock enjoyed tea.

He was on his fourth cup, noting a discomfort in his bladder but a lessening of the pain in his head, when there was a firm knock on his door.

"Come," he said weakly and saw himself enter.

"A miracle," McCoy exclaimed. "It's a damned miracle."

"I do not understand," Spock said, and he wished that McCoy would lower his voice.

"What happened to us," McCoy continued. "It's a cornerstone of their religion."

"Oh?" Spock asked.

"They believe it's a sign from their gods, that the people affected have been chosen for a greater purpose. If we were to tell them what happened, we'd be made village elders. That's how they're selected."

"I see," Spock said.

"They've got a whole mural dedicated to it, similar to the hieroglyphs in Ancient Egypt back on Earth."

"Did they say anything about being able to reverse it?"

"No," McCoy said, pacing the length of the room. Spock steadied his hands on his knees. "They have no idea what causes it, that it's even _possible_ to cause it themselves. But the artwork did show the two Silviaans in the right bodies again, in the end. Uhura was sure of it."

"We can hypothesize they seek no remedy when this occurs," Spock reasoned. "Thus, perhaps the transfer is only temporary and will reverse on its own."

"But how long does it last? They didn't say anything about it reversing, and Uhura couldn't glean anything from the mural about it."

"Did you capture a likeness of the mural?"

"No tech in the temple," McCoy muttered and rubbed his arms. "Jim's orders."

Spock allowed himself a smile but shook his head.

"Figures he'd choose today to obey the Prime Directive," McCoy added.

***

Mid-morning, McCoy's comm received a text from Lt. Marcus wishing him a speedy recovery. Spock found himself exceptionally pleased by the fact that her attention was directed at Dr. McCoy and not at the captain. He took it upon himself to write back, indicating his thanks and suggesting they dine together in the near future. Jim often expressed a desire to see McCoy in a pairbond. Lt. Marcus's affirmative response was encouraging.

Spock ate a late lunch in McCoy's quarters, a plate of chicken fried steak. What a curious name, since the dish contained no chicken at all. He stared at the chunk of beef on his fork suspiciously before putting it in his mouth. He grimaced at the idea of consuming animal flesh, but the taste was excellent. He chewed languorously, studying the texture of the meat between McCoy's teeth, the crunch of the fried breading. It was not his body, after all, and as a scientist, it was fascinating to be able to study this first hand. He swallowed and ate another bite, holding it up to look at it first, study the stringy appearance of the muscle fibers.

He finished the entire plate and replicated another, this time requesting a barbecue pulled pork sandwich. He had heard this was typical of Southern American cuisine, and he was not displeased with the flavor. He ate greedily and was halfway through the plate, suddenly aware of the grease on his fingers, when the door sounded.

"Come," he said through a full mouth and quickly wiped his hands on a napkin.

"Hey," Jim said glumly, dropping onto the couch next to Spock.

"Hello," Spock replied, clearing his throat.

"Feeling any better?"

"Somewhat. How was your meeting with the elders?"

"It was okay," Jim said. "Spock was really fascinated by their religion, so he and Uhura kind of took over the conversation at one point, which was nice. I didn't have to do a lot of bullshitting."

He stretched his arms over his head, yawned, and rested them on his stomach. Spock tried to mimic his posture and leaned back, feeling awkward.

"You indicated a need to talk?" he said. Jim frowned at him and laughed.

"The hell's up with you today?" he asked. Spock scratched the side of his face and tried to recall how McCoy generally handled these meetings with Jim.

"Bourbon?" he offered.

"It's not even dinner time," Jim commented. "Rough day?"

 _Indeed_. "Yes," Spock replied.

Jim sighed and rubbed his forehead.

"Fine," he said. "If you're having one this early, I will too."

Spock rose and went to the gathering of bottles on top of McCoy's dresser and poured a measure of bourbon in two glasses. He held one out to Jim, who downed his in one gulp.

"I believe bourbon is meant to be sipped," Spock informed him as he settled back onto the couch and took a sip. It burned his throat, but he drank anyway. "What is wrong?"

Jim looked at him funny but sunk lower in the chair. "I have to tell you something," he said. "Don't laugh."

"I sha—" Spock began, then corrected himself. "I won't."

Jim took a deep breath. "I think I'm in love with Spock."

Spock choked on his bourbon and coughed violently. Jim smacked him on the back.

"Are you okay?" he asked. Spock nodded and pressed a fist to his lips. "Sorry, I should've prefaced that somehow."

"It is..." _quite unnecessary to apologize_. "...fine," Spock said, fighting the urge to smile. "Go on."

"I should have told you before now," Jim continued. "It's just that at first, I didn't know if it would last, and then...well, now it's gone on long enough that I feel stupid for not telling you about it in the first place."

Spock nodded and took his glass back up between his hands, so his fingers had something to do. He itched to touch Jim, having heard his declaration. He wished to wrap Jim in his arms and hold him. In this human form, he found his affection for Jim was unchecked. He must remain in full control of his faculties.

"Anyway," Jim said, "I thought everything was going well, like... _really_ well, you know? I mean, Bones, you know me. I've never..."

"You have never been in love?" Spock guessed, his heart rate increasing.

"Maybe a little," Jim admitted quietly, "but not like this."

"Shouldn't this make you...happy?"

"Yeah," Jim said. "It has been. But yesterday, he started acting...I know you're going to tell me that he's Vulcan, and that I can't judge the way he's acting by human standards. I get that, but I know him. I know how he acts around me, and..."

"What happened?" Spock asked, daring to rest a hand on Jim's forearm. He had seen McCoy touch people in this manner.

"He wouldn't kiss me last night," Jim murmured. "He said he was sick, so I let it slide, but today on planet..." He bit his lip. "A few weeks ago, he taught me the Vulcan equivalent of kissing. They touch their fingertips together. It's...polite, and it was weird the first couple times, but it's really sweet. He gets kind of soft when we do it, so I...like it."

Spock nodded but kept his mouth firmly closed.

"When we beamed down this afternoon, after everyone walked away from us, I held out my hand, but he wouldn't touch it. He just stared at it, like he had no idea why I would do that."

Spock winced and swallowed. Jim had never initiated that action before, and he had missed it. His heart sank.

"What did you do?" he asked.

"What do you think? I laughed, played it off like a joke, walked away."

Jim stood for a refill of his bourbon and this time brought the bottle back with him. He held the glass in his hand and swirled it.

"You are afraid he does not return your affection," Spock said.

"Pretty much," Jim said flatly.

"Jim," Spock said, "I am certain he does."

"Yeah, right."

 _Perhaps_. "Maybe...it was the situation."

"What do you mean?"

"Lieutenant Uhura was present, correct?"

"Yeah."

"Her presence could have made Spock...uneasy. You know how those..." He steeled himself before he uttered the next word, attempting to phrase it with a hint of disdain. "...Vulcans can be. Perhaps he was uncomfortable expressing his affection for you in front of her."

"Are you sure you're okay?" Jim asked, raising an eyebrow.

"I am fine."

"It's just that you seem a little...off."

"I did not sleep well last night."

"Me either," Jim muttered.

"Have you considered telling Spock how you...feel about him?"

"Oh, sure. I'll just tell my extremely Vulcan first officer all about my human emotions."

"He might not find it as distasteful as you imagine."

Jim cast him a sideways glance. Spock stared into his glass.

"Would you like me to speak with him?" he offered.

"No," Jim said. "I don't want him knowing I came crying to you like a teenager. For all I know, he wants to keep what's going on between us private. He's never said otherwise, and I didn't want to push it."

He poured a third glass and drank it. He held out the bottle, and Spock nodded that he too would take another.

"Figures I'd fall for someone even more emotionally stunted than me, huh?"

They sat there in silence for a long time. The alcohol had gone into Spock's bloodstream, and he lost count of the minutes. He felt relaxed and lazy, and very warm. His fingertips were flushed pink, pink like Jim's lips, which were pressed to the rim of his glass as he took another sip. Spock watched him, the way his adam's apple bobbed as he swallowed, how he tapped his left index finger against the glass. Jim closed his eyes and rested his head against the wall, breathing quietly.

Spock's head swam with bourbon, and Jim loved him. Jim _loved him_. Jim was beautiful, just inches away. Spock reached out a hand and stroked Jim's cheek, smiling lazily. He leaned forward and kissed him. Jim's eyes fluttered open.

"Woah," Jim said softly, pulling away. "I think you've had a little too much bourbon, doc."

Spock went rigid and sat upright, covering his mouth.

"I..." he started. "I'm sorry."

"Don't worry about it," Jim said, slapping his shoulder. "We should probably get something for dinner. I couldn't eat what they were serving us at the luncheon. Want to head to the mess?"

Spock shook his head. "There are things I must attend to," he answered.

"Okay," Jim said. He rapped his knuckles against the door jamb before he exited. "Thanks. And listen, don't worry about...this. Okay?"

"Jim?" Spock called when Jim was outside the door.

"Yeah?" Jim said, poking his head back inside.

"Invite him for chess," Spock said.

"I'll think about it," Jim said, and the doors closed. Spock dropped his head into his hands. What had he done? He must correct this. He fumbled for the comm and dropped it onto the floor before he managed to open it.

"Spo—McCoy to Spock."

"Spock here," McCoy said in a hybrid Vulcan drawl.

"We must speak," Spock said.

"Can you come here?" McCoy asked. "It's freezing in my room."

"I will adjust the temperature," Spock told him. "I do not believe myself capable of walking."

"My god, are you drunk?"

"Yes," Spock said. "It is...curious."

"I'll be right there," McCoy said. "Don't you move."

***

"Before you ask," Spock informed McCoy through a single eye, "I am, in fact, out of my Vulcan mind. I am in a human mind, which is responsible for my behavior."

"You got yourself drunk," Bones said, looking down at where Spock sat miserably on the couch. "My brain didn't make you do that."

"I should not have kissed him," Spock lamented.

"Well," McCoy said, chuckling, "if it makes you feel better, Jim's drunk kissed me a couple times in the past."

"Indeed?" Spock said, lifting an eyebrow.

"Not like that," McCoy said. "One was a dare, the other...he was in a pretty bad place. I picked him up from a bar, brought him home."

"He mistook your kindness for attraction?"

"He was heartbroken," McCoy said. "I think he was trying to forget that. How'd it happen, anyway?"

"He said he loves me," Spock announced, and he smiled as he lay back on the couch. McCoy scoffed.

"Congratulations. You should see what you're doing to my face," he said. "It's unnatural."

"I thought that I loved Nyota," Spock told the ceiling.

"Oh, lord," McCoy muttered and pinched the bridge of his nose.

"I did care for her deeply."

"Why did you have to get drunk today, of all days?"

"She often said she cared for me," Spock continued. "I found her declarations pleasant, but I did not feel like this."

"Love does things to a man." McCoy sighed and sank into his desk chair.

"You suggest I love Jim in return?"

"I'm not suggesting anything," McCoy said. "You're over the moon for the kid."

"He is _t'hy'la_ ," Spock said and blushed, covering his mouth. "I have never spoken that word before."

"What does that mean?"

"For me, it means Jim."

"I'm going to go out on a limb here and assume you're not talking about platonic friendship."

"You must play chess with him tonight," Spock said, struggling to sit up.

"I don't play chess," McCoy told him.

"You must," Spock repeated. "I instructed him to invite you. He believes I do not return his affection."

"As soon as we're switched back, you can straighten it all out for him."

"Please," Spock said, and the word was so foreign coming out of his mouth that McCoy paused.

"You know, we're supposed to be working out how to switch back into our respective bodies, not planning chess dates with Jim."

"He prefers it when I wear black," Spock informed him.

"I'm wearing blue," McCoy said firmly.

***

In the interest of his own sanity (and virtue), McCoy invited Jim to a chess game in the mess, hoping the public location would be enough to forestall any flirting. If Jim chose to flirt with him anyway, at least McCoy would have the excuse of being in public to refrain from doing anything in return. That seemed fairly Vulcan of him. They'd spend a pleasant evening together over a game, and then McCoy would feign an excuse to go to the labs. Jim never followed him there, Spock assured him.

Jim met him in the mess, still in his uniform from alpha shift, but with that same look he'd given McCoy down on Silvis VII.

"Hey," he said. "Sure you wouldn't rather play in your quarters? It's warmer."

McCoy shook his head, comfortable in his thermal, two undershirts, and his blue tunic. And without Jim Kirk's hands all over him.

"I'm fine," McCoy said and motioned to the table where Spock had set up the chess set. He lingered on the opposite side of the mess, mulling over a PADD. He looked appropriately grouchy, McCoy decided. It was unlikely anyone would approach him.

"Do you want something to drink?" Jim offered. He motioned to the replicator bank.

"Tea," McCoy answered, and Jim looked happy as he went to order it.

McCoy, who had never been a chess aficionado, found himself playing pretty damned well. Between Spock's crash course and a Vulcan brain, the moves were...obvious and (god help him) logical. He made the opening moves Spock had instructed, and Jim immediately concentrated his focus on the board. To McCoy's relief, Jim kept the flirting to a minimum, though McCoy had to move his foot out of the way both times Jim tried to nudge his instep.

"Thanks," Jim said to him, quietly, as he put the chess pieces back into the small compartment. "This was fun."

"It was," McCoy agreed.

"I guess you're going to go off and do science stuff now."

"Yes." McCoy cleared his throat. "I have several experiments I have to check on."

Jim scraped his boot on the floor. "Is it okay if I come by later?" he asked. McCoy's voice stuck in his throat, and he cleared it roughly.

"Jim," he said, buying himself a few seconds to think. "I will be in the lab quite late."

"I'm not sure which is worse: your work ethic or my insomnia."

"I thought you've been sleeping better?" McCoy asked, rounding on him. It occurred to him that he sounded like himself rather than Spock, so he lowered his voice. "You have slept...well, when you're with me."

"Yeah," Jim said, touching his arm briefly. Even through the sleeve, McCoy got a good picture of what was going on in Jim's head. He got a flash of Jim's legs wrapped around his waist, his back against the shower wall, and shuddered. "And I could use a good night's sleep tonight."

Jim looked at McCoy with both eyebrows raised. McCoy swallowed and chanced a glance at Spock, who was watching them intently over the top of his PADD. He looked back to Jim and nodded.

"I believe Dr. McCoy requires your attention," he said and inclined his head. "Goodnight, Jim."

He turned and walked away before he could see Jim's face fall, the way he knew it would. Once he was in the turbolift, he found that he had no desire to go to his room. If Jim followed him there and found he'd lied about going to his lab, he'd have even more problems than he did right now. Hell, maybe Spock was right and they should just fess up to the whole thing. It had seemed like a good idea to keep it quiet when it first happened, but now that it was almost forty-eight hours later and they were no closer to getting back into their rightful bodies, McCoy had to wonder if he'd acted rashly on surface.

He considered paging Spock, telling him just that, asking what he thought about telling Jim now. But Spock was probably consoling Jim, probably drinking more of McCoy's good bourbon. Spock owed him a bottle after this.

McCoy was surprised to find Carol in the lab, bent over a microscope. She brushed a strand of hair from her face and tucked it behind her ear. He felt a strange fluttering in his side at her action, and he looked down at his ribcage nervously. It was a few seconds before he remembered that his heart was in his side. He reached a hand to it and scowled. Carol scribbled something on her PADD and stood back. McCoy cleared his throat to alert her to his presence; she obviously hadn't heard the door open. She straightened immediately, smoothing the hem of her uniform.

"Commander," she said.

"Lieutenant."

"I thought the lab would be unoccupied. Am I disturbing you?"

McCoy shook his head. "The last time I checked, this lab's open to all members of the science department."

She looked uncomfortable but held her smile in place. He folded his arms behind his back and walked toward her.

"What are you working on?" he asked.

"Oh," she exclaimed and turned back to the microscope. She adjusted the sample under the lens and flipped a switch, which projected the image in the air before them. "It's a mineral I found on the surface. We don't have anything like it on Earth. I'm evaluating its potential as an energy source."

"Aren't you a weapons specialist?" McCoy asked and raised an eyebrow. He pretended to look at the sample, which was black with occasional rainbow-colored fragments. She gave a noncommittal shrug.

"My father thought it was prudent that I study in that field," she said. "Of course, in retrospect, I see why."

"I'm sorry," McCoy offered.

"Anyway," she said, "my real interest has always been how we might use sub-atomic particles to terraform planets which are currently uninhabitable but have the potential to be Class-M."

"The purpose being?"

"The possibilities are numerous," she said. "It could be used as a penal colony, for cultivation, or as a solution for overcrowding. We could even use it as a living laboratory." She lowered her chin. "And of course, it could be used for emergency relocation, in times of crisis."

"You're talking about the destruction of Vulcan."

She nodded. "It was fortunate a suitable planet was found so quickly, but if there had been a way to recreate a specific set of conditions—atmosphere, plant life—the adjustment would have been easier."

"It's rare," McCoy said, "to have to relocate an entire planet."

"But not unheard of," she said. "After all, we know that Romulus must be evacuated within the next hundred years. I'd like to be able to give them a world that is...familiar."

"You want to give that to the Romulans?" he said flatly. She winced and shook her head.

"I'm sorry," she said. "I can't imagine how that must sound to you, considering what Nero did to your planet."

"No," McCoy said. "That's...compassionate of you."

"Thank you, Commander." She switched off the microscope. "I should get dinner before it's too late."

"Of course."

"Did you already eat?" she asked.

"I did."

"I don't suppose you noticed if Dr. McCoy had eaten?"

McCoy blinked at her and pressed his lips together to keep from looking surprised. "I..." he began. "He was in the mess when I left."

Carol seemed to brighten a hint. "Goodnight, Commander," she said and exited the lab. McCoy counted her footsteps as she walked away—ten, eleven, twelve—until he couldn't discern them from the ambient ship noise.

***

Spock felt a jolt of excitement in his midsection when his comm chirped, but when he opened it, the message was from McCoy. It alerted him that Lt. Marcus was on her way to the mess, and that she expected to have dinner with him. McCoy advised him to stay, so he did, fidgeting with his sleeve, tapping his foot on the ground. Illogical, he told himself, and yet he could not still his extremities.

He was disappointed that the message was not from Jim, though he had come by to speak with Spock briefly before leaving the mess. Jim had said little and appeared perturbed, despite what Spock deemed a successful game of chess with McCoy. Spock had suggested they enjoy another drink and speak further, but Jim had merely clapped him on the shoulder and laughed.

"I think we had enough for one day," he said. "See you in the morning."

Jim had gone, and Spock was unhappy.

He watched Lt. Marcus enter, watched her move to the replicator bank and select her meal. He saw her glance casually around the room, as though she did not realize he was present. He knew this to be untrue because of McCoy's message and lamented the human lack of logic.

Sighing, he raised his eyes to her and nodded once. She looked grateful as she crossed the room and slid in across from him.

"Hello," she said, and her smile was warm and quite lovely, Spock had to admit. McCoy's body seemed to be quite taken with her.

"Hello," he replied and folded his hands in front of him. He recalled the way Jim always began their evenings together. "How was your day?" he asked.

"Busy," she said, "but satisfying. You?"

"I was unable to report for my shift this morning," he said. "My day was unproductive."

"I hope you're feeling better," she said and placed a hand on his forearm. Though Spock inwardly cringed, McCoy's heart beat oddly in his chest. Fascinating.

***

Spock did not expect to find Jim sitting at the desk when he entered McCoy's quarters forty-five minutes later, already a glass in.

"Changed my mind," he said and held the glass up miserably as the doors closed.

"You should have alerted me," Spock said.

"Now _you_ want me to go?" Jim said, throwing his hands into the air. He drank the remainder of his glass in one swallow and stood. "Sure, why not. I always was better off by myself."

"That is not what I meant," Spock said, catching Jim's arm as he rose. It was strange to possess the same strength as Jim. It was typically easy to maneuver him, but Spock held tightly to his arm as Jim pulled out of his grasp. "I would have left the mess sooner, if I had known you were here."

"I think it's over," Jim said, slumping against the wall.

"Over?" Spock repeated.

"The thing with Spock. You saw us play earlier, right?"

"I did."

"We usually play in private, but he wanted to play in the mess for some reason. I asked if I could come by and see him later, but he said..."

Jim screwed his face up and looked down at his hands.

"Yes?" Spock prompted.

"He said you were looking for me, actually. Then he left." Jim caught the lower half of his face in his hand and took several breaths. Spock was quiet, watching him. "How'd I manage to fuck this up?"

"I am certain that you have done nothing wrong."

"Have you heard anything? Have people said anything?"

"No."

"Do you think he's back with Uhura?"

"He is not," Spock said firmly.

"I feel like an idiot," Jim said. He let the hand fall away from his face and leaned against the wall behind him.

"You must calm down," Spock told him.

"He's probably been trying to break it off for a while, and I've been too stupid to notice the signs."

"Sit on the couch," Spock directed. It was a moment before he complied, but Jim fell onto it and pressed his face into a pillow.

"I should just take a page out of your book," came his muffled voice. "Stick with the bachelor life."

"You do not mean that."

"It's probably best in my position," Jim said, rolling off of the pillow so his face was visible again. Tentatively, Spock sat next to him.

"Because you are the captain?" he asked. Jim nodded a few times.

"This ship is supposed to be my primary relationship," he said.

"Do you believe yourself to be neglectful in your duties?"

"I shouldn't be in my CMO's quarters with personal problems," Jim said flatly. "We should be discussing mandatory inoculations, not my relationship with my first officer."

"On a mission such as this," Spock said, "it is...natural that relationships form between crewmembers, and natural that you wish to discuss them.."

"Since when are you a psychiatrist?" Jim shot back.

"Regardless of what I often say," Spock informed him, "the psychological health of the captain is my business."

"Yeah? I'll remind you of that the next time it comes up."

"Please do," Spock said.

"Can you hit me with one of those sleep aides?" Jim asks. "I'm not going to be able to get an hour tonight. My mind is racing."

"Of course," Spock said. "I will ask Nurse Chapel to prepare the proper dosage, and I will bring it to your quarters."

"Did I finally run through your hidden stash?" Jim asked. Spock refrained from lifting an eyebrow, but he wondered how many times Jim had required medication to help him sleep in the past. He suppressed the desire to pull Jim to him and instead clamped his hands together.

"You did," he said.

"Think you'll be back to work tomorrow?"

"Uncertain," Spock replied.

"Yeah, you don't look great," Jim said. "You look a little flushed, actually."

"It is quite warm in here."

"Man, I think you've been hanging out with Spock a little too much," Jim said, "except Spock would never say it's warm anywhere."

He laughed, but it faded in seconds. Jim stood up and stretched his arms over his head.

"I will bring a hypospray by your quarters shortly," Spock said.

"I'm going to hit the gym first," Jim told him, "see if I can run some of this out of my system. I'll comm you when I'm back."

***

Rather than wait in his quarters for Jim to contact him, Spock headed for C Deck, to his own room, and punched in his override code when McCoy didn't answer. He inhaled the welcome fragrance of Vulcan incense and sank to the ground next to the bed, trying and failing to reach a meditative state. He was wont to admit that he lowered the thermostat, finding his regular standard overly warm in his human body. He wondered if Jim had ever felt this uncomfortable in Spock's quarters. If he had, Jim had never complained. Spock was touched by what that knowledge did to him. His heart stuttered in his chest, and he placed one hand over it, as though it would steady the beating.

McCoy was in the labs, according to the message he sent back when Spock inquired as to his location. Spock should follow him, but he felt no compulsion to do so.

He'd been sitting for an indeterminate length of time when the bathroom door opened.

"Listen," Jim blurted, coming into the room. He wore red exercise pants and a loose-fitting t-shirt, and rubbed his hair with a towel. "About earlier—"

He stopped talking when he saw Spock and froze, a look of confusion clouding his face. He looked around the room, presumably for Spock, who from Jim's point of view would not appear present. Spock considered how the situation must look to Jim: he had entered Spock's quarters to find McCoy there alone, seated on the floor beside the bed. Surely this could not be quickly explained away, and from the hurt look that sliced across Jim's face, Spock might not have a chance to try.

"Jim—" he began, getting up, but Jim held out a hand.

"No," he said darkly, draping the towel around his neck. "Really. I should've knocked."

"It is not what you think."

"No?" Jim asked, and his eyes were wide.

Spock walked to his side. "No," he said quietly. Jim swallowed audibly, glancing around them, and folded his arms over his chest.

"I think I just found my best friend in my first officer's room."

"You did," Spock confirmed. "However, you do not possess all of the relevant information in order to—"

"And what the hell is with you lately? How long have you two—is that why you're talking like this?"

"Jim, no. I assure you—"

"No wonder it wasn't a problem for you to bring the hypo by my quarters. You were probably laughing when I told you he tried to get rid of me earlier. Jesus, Bones!" Jim's voice wavered, and he balled his hands into fists.

"I would never laugh at your expense," Spock told him earnestly and took his arm. Jim tried to shake him off.

"I really want to fucking punch you right now."

"Your confusion is understandable but unnecessary."

"And that kiss earlier...was that to confuse me? What is this, a threesome invite?"

"No," Spock said hurriedly. "I assure you that Dr. McCoy and I are not romantically involved."

He winced when he heard the words leave his mouth, but he held firmly to Jim's arm. Jim's frown deepened, and he shook his head, but his mouth dropped open. He tilted his head to the side and blinked, and some of the anger disappeared from his face. He looked at Spock, then down to the hand on his arm, and finally stopped his eyes on Spock's chest. Spock was breathing hard, could hear his own heartbeat in his ears. His hands were shaking, but he held one out to Jim with two fingers extended.

"Spock?" Jim whispered and met his eyes again.

Spock pressed his lips into a line and nodded minutely. His hand wavered in the air; Jim touched it briefly, and Spock flooded with relief.

"How?" Jim asked.

"Do you recall the flower that Dr. McCoy and I would not allow you to touch?"

"Sure, because Spock about took my arm—oh. _Oh_. Why didn't you tell me?"

"If you were made aware, Dr. McCoy was concerned that regulations would require us to be restricted to sickbay and incapable of securing a method to transfer back into our respective bodies."

"But you're still...him."

"Our research has been unsuccessful."

"Huh," Jim said, the muscles in his arm loosening underneath Spock's grasp. He sunk to the floor, and Spock kneeled beside him. "So you're telling me that last night, when I came into the room in just a towel, that was Bones I tried to proposition?"

"Yes," Spock admitted.

"And earlier today, on the surface, that's why he didn't kiss me back."

"Affirmative."

"So that was you I told about my feelings for... _you_."

"It was."

"Sorry," Jim offered and averted his eyes.

"Do not be," Spock said and brushed the hair from Jim's forehead. Jim bit his lip.

"You really don't mind?" he asked.

Spock shook his head and arranged Jim's hair again.

"That's why you kissed me," Jim realized.

"Dr. McCoy's bourbon had an unexpected effect on me in this form," Spock said quietly. "I found I could not resist you."

Jim beamed up at him, but it was short lived.

"You should've told me," he said. "As your captain, I have a right to know. And as your...whatever we are, I think I had a right there too."

"You are mine," Spock said. "That is enough for now. And I wish I had told you." He took Jim's hand in his and stroked two fingers along the back of it.

"This is so weird," Jim commented, though he shivered.

"How so?"

"Because you look and sound like Bones," Jim said. "What about that mind meld you guys do? Will it work like this?"

Spock shook his head. "I do not possess any telepathic abilities in this form."

"Damn," Jim said. "I'd feel pretty weird kissing you while you're in Bones's body."

"Perhaps," Spock suggested, "if you close your eyes?"

Jim did, and Spock leaned in and kissed him softly, curving a hand around Jim's jaw. He stroked a thumb against his cheekbone.

"Nope," Jim whispered, and he pulled back. "Definitely weird. Can't do it."

"Will you permit me to stay while you sleep?" Spock asked.

"I guess so?" Jim said and shrugged.

"I brought the hypospray that you requested."

Jim smiled at him. "Don't think I'll need that anymore."

"I regret that I upset you."

"I'm sorry I thought you were sleeping with Bones. I was going crazy the last two days."

"Do not doubt my regard for you again," Spock said fondly. "Had I known you desired a monogamous relationship with me, I would have readily agreed."

"I can't wait until you're back in your own body," Jim said. Spock looked at him seriously.

"Jim," he said, "we must accept the possibility that Dr. McCoy and I may be unable to switch back."

Jim nodded softly. Spock settled next to him on the floor, and Jim leaned his head against Spock's shoulder.

"You're the smartest person I know," Jim said quietly. "I'm sure if there is a way, you'll find it."

"Your faith in me is reassuring," Spock said. Jim laced their hands together.

"So's this," he said.

They sat that way until McCoy entered the room a while later. Spock had not bothered to keep count of how long. He was content feeling Jim's hand within his and was hardly moved by the glare McCoy shot at him.

"I'm going to assume you told him," he said to Spock and pulled out the desk chair. He sat down roughly and stretched his legs out in front of him.

"He did," Jim said, raising his head, but he kept a hold of Spock's hand. "And before you ask if we slept together, _no_ , we didn't."

"Well, that's a relief," McCoy muttered. "How'd it go with Carol?"

"She touched your arm three times while we ate and indicated a desire to take her morning meal with you as well," Spock reported.

"Great. I finally get somewhere with a woman, and I'm not even around for it."

"What are we going to do?" Jim asked. "If we can't find a solution, I'm not giving up my CMO and my first officer."

"My productivity is reduced," Spock said, turning to look at Jim. "I am not capable of fulfilling both of my current positions. You would be best to relieve me of one. I would recommend the first officer's position. My scientific knowledge is still vast, but it will require more of my time."

"What about you?" Jim asked McCoy, who raked a hand through his hair.

"You'd have to get my medical license adjusted, most likely. I feel sharp as hell, but I sure don't look like the guy who holds my license. I'm guessing there's a lot of red tape we're up against."

"I don't want either of you leaving this ship," Jim said firmly. "Whatever we need to do, we'll do it."

"You need sleep," McCoy told him. "You look beat. Do you want your usual?"

"Yeah," Jim said and squeezed Spock's arm. McCoy looked appropriately scandalized. "I'm not going to take advantage of you," Jim said with a roll of his eyes.

"Oh, no," McCoy said. "You are not using me as a pillow."

Jim laughed and stood up, holding his hand out to Spock, who took it and got to his feet. Jim didn't release his hand, and Spock felt a warmth spread into his cheeks because of it.

"Don't you dare," McCoy barked as Jim began to back toward the bathroom with Spock in tow. "Spock, say something logical."

"Jim is tired," Spock replied. "I am going to see he receives adequate rest."

"Even as a human, you're intolerable!"

"And your xenophobia knows no limitations," Spock said lightly. "Goodnight, doctor."

"Goodnight, Bones," Jim echoed and opened the door to the bathroom. Spock kept his eyes on the back of Jim's neck as they crossed into Jim's quarters.

"Just sleeping, right?" Jim asked as he pulled his tunic over his head.

"I think it is best," Spock told him.

"I'd give you a show," Jim said, splaying a hand on Spock's chest, "but I don't know if I could keep a straight face through it."

Spock chuckled—what an odd sensation, to laugh so freely—and leaned his head against Jim's.

***

There had been one incident that resulted in Jim Kirk's presence in Leonard McCoy's bed, but that was years ago, back at the academy, and had been purely out of necessity. He hadn't trusted Jim to stay put in their apartment following his split with Gary, so he'd wrestled him into the covers and hit him with a sleep aide. Jim had slept twelve hours straight and woke up requesting pancakes. McCoy had spent the night on the floor and woke with a stiff neck.

Though he wasn't thrilled to admit it, he hadn't shared his bed with anyone since they left on the five-year mission. There had been a few women at starbases when they stopped for supplies, but they'd never come back to the ship with him. He was surprised to wake up and feel an arm slung over his chest and someone breathing into his shoulder. His body liked it. He sighed and rolled into her, opening his eyes with a lazy grin, and looked into Jim Kirk's smiling face.

He immediately pulled his hips back, and his erection died. Jim smirked at him.

"Oh," he said knowingly. "Morning, Bones."

"Get your arm off of me," McCoy growled at him.

"How 'bout you get out of my bed?" Jim replied.

"Go find your boyfriend," McCoy snapped as Jim happily crawled over him (wearing pants, thank god) and went into the bathroom. McCoy sat up and stretched, and did a quick mental check of his body to make sure he wasn't sore anywhere he shouldn't be. Well. That was a relief.

Jim poked his head back out and spoke around his toothbrush.

"Bones," he said. "Glad to have you back."

***

Spock stretched into the warm, familiar air and inhaled deeply when the mattress dipped beside him. He felt two hands sneak under his night shirt and up his sides, and the weight of Jim's body came to rest on top of him.

"I believe we said sleeping only," Spock reminded him groggily.

"That's when you were still Bones," Jim whispered into his ear. "Check this out."

Jim sent a wave of lust through him, and Spock's eyes fluttered open. He blinked until they watered and he was able to make out the Vulcan artifacts that adorned his room, the red wall coverings, the unmistakable blue of Jim's eyes.

"See?" Jim said.

"It appears I have returned to my rightful body."

"It appears you have a hot guy in bed with you."

"Indeed."

"Planning to do something about that?"

"Indeed."

He rolled Jim onto his back and ground their hips together until Jim was moaning in appreciation. Spock was immensely pleased by the sight of Jim sprawled out beneath him, his neck and chest flushed deep pink. Jim writhed against the sheets and scraped his fingernails along Spock's back. Encouraged, Spock slid down Jim's body, stopping to press his face into Jim's stomach, hollowed out as he arched off the bed.

"I want your mouth," Jim whined.

Spock groaned and sucked him down. He kept his hands on Jim's hips and pinned him to the bed. When Spock looked up, Jim was watching him.

"That feels so good, just like that, just like that," Jim chanted and let his head fall back against the pillow. "Just like that."

Jim's hands were balled into the sheets when he bucked up into Spock's mouth and unleashed his usual verbal torrent which accompanied orgasm. It culminated with something Jim had never said to him before, and Spock stilled when he heard it.

"I love you. Fuck, I love you."

Spock pulled off gently and crawled back up Jim's body, covering them both with a sheet. Spock kissed him in between breaths and nipped at his jaw, mouthing to the curve of Jim's ear. He hesitated, panting against it, and kissed it once.

"Your affection is reciprocated," he murmured, and Jim's arms tightened around him in response as he laughed.

***

McCoy prayed no one would see him leaving the captain's quarters with bedhead and a wrinkled uniform. He kept a scowl firmly planted on his face until he reached his own room and stalked into the shower. He scrubbed himself awake after ensuring Jim hadn't left any bruises on him, opting for a water shower. He stood with one hand on the shower wall and let the water stream over his face and hair. He hadn't been this warm in days.

Dressed in a clean uniform, he debated replicating something in his own room but decided on the mess. He wanted third-party confirmation that he was, in fact, Leonard H. McCoy. He strode to the mess and took a tray, looking around the room to see who was present.

Carol was seated by herself at a small table against the wall, reading something on a PADD. The glow of the screen reflected on her face, and he had to smile at the way she pursed her lips and nodded to herself as she read. He replicated a plate of apple pie and a strong mug of coffee, and walked over to where she was seated. When she looked up at him, he gestured to the chair across from her.

"Mind if I join you?" he asked. At her smile, he set down his tray and pulled out the chair, settling in and biting back his own grin.

"You seem in better spirits today," she commented and drank from her mug.

"I think I'll be in better spirits for a while," he said and raised his own mug in salute.

"Pie for breakfast?" she asked, raising both eyebrows.

"It's been a long couple of days," he replied and forked the edge of the crust. It wasn't nearly as good as homemade, but damn, it was a treat compared to that broth Spock was so fond of. The replicated butter flavor was just this side of bitter. He swallowed happily.

"Are you beaming down to the surface?" she asked, and he frowned.

"Why would I beam down to the surface?"

"The captain ordered an extra day of leave for everyone," she explained.

"Oh, did he now?" McCoy mused.

"All non-essential personnel are allowed half a day on the surface. I was thinking of going for an hour or two. Nyota says there's a beach."

Carol looked at him expectantly.

"Well, in that case," he said, dabbing his mouth on a napkin, "I'd be delighted to go, if you'll accompany me."

"Thank you, Dr. McCoy. I would like that."

"Leonard."

"Leonard," she repeated and smiled.

***

Spock pointed to where McCoy walked arm-in-arm with Lt. Marcus, bringing the development to Jim's attention. As he suspected, Jim was pleased with the turn of events and touched Spock's arm briefly. Though there were several crewmembers near them, he extended two fingers to Jim. Jim bit his lip and touched Spock's hand in return, though there was nothing innocent in his action. He slid his fingers against Spock's and sent him a series of explicit mental images. Spock found himself anticipating their evening together and illogically wishing that it were already later in the day.

Jim had to beam up early to take a call from the admiralty, and while Spock offered to accompany him, Jim clapped his shoulder and told him to stay.

"I expect you in my quarters at 21:30 sharp," he said, touching the edge of Spock's sleeve.

"I will report as ordered, Captain."

"And there's a dress code," Jim continued. He looked up and caught Spock's eyes. "No clothing permitted."

"I will endeavor to obey."

Jim winked and commed the ship for beam up. Spock remained by his side until Jim was enveloped in the transporter's beam. He smiled at Spock as he dematerialized, and Spock felt warm.

It wasn't often that Spock took shore leave, less often that he took it without Jim or Nyota. He found an odd pleasure in exploring the village by himself, in observing the native people. In the town center, he came upon a public performance: a man and a woman who are given the divine gift of switching bodies. Spock raised his eyes to the roofline and suppressed a sigh. At the play's conclusion, he bowed his head slightly in recognition of the effort and made his way back to the beam-up point.

It was there he encountered McCoy, who held a small package in his hands. Spock approached him and raised an eyebrow in question.

"For Jo," McCoy explained. "She gets a kick when I send her things from other planets."

"I hope you are not sending her samples of the native plant life," Spock said. "Where is Lt. Marcus?"

"Went back up to the ship," McCoy said. "Had to check on something in the lab. Said she'd be a few hours."

"I see," Spock said. "I am pleased to see she accompanied you."

McCoy looked surprised. "Thanks. I'm pretty pleased myself."

"You are not angry that I encouraged her to pursue you?"

"No, I'm grateful, actually."

The wind blew across the field where they stood, stirring up the honey-sweet fragrance of wildflowers. It made Spock involuntarily shiver. He picked his foot up to ensure he was not crushing one.

"Feels like they're out to get you, doesn't it," McCoy said with a grin.

"My negative experience with psychotropic plants is limited to this incident, yet I distrust all flowers in the immediate area."

"That's hardly logical," McCoy chided. "Maybe some of my humanity rubbed off on you."

"Perhaps," Spock replied. "I can only hope some of my logic has remained with you."

"I'll take logic over those ears," McCoy said and sniffed. He looked away. Spock looked at the ground.

"Jim is taking a call from Starfleet Headquarters," he offered after a pause.

"Looks like it's just us," McCoy said, rocking forward onto the balls of his feet.

"In that case, doctor," Spock said, "I wonder if you would join me for dinner?"

"Dinner?" McCoy repeated.

"We must discuss what we intend to submit in our report to Starfleet regarding the flower in question."

"I see," McCoy said.

"Further," Spock continued, clearing his throat, "I believe the events of the past two days have made us friends. I understand it is customary for friends to take their meals together."

"Why, Spock," McCoy said. "That might be the nicest thing you've ever said to me."

"Are you accepting my offer?"

"Well, I'm sure as hell not rejecting it," McCoy said and slapped him on the back. "We can eat in my quarters. From my replicator's history, I understand you took a liking to barbecue."

"The taste was not unpleasant, however I have no desire to eat meat now that I am back in my body."

"You say that now, but wait until the next time we're back on Earth. I'll show you some real Southern cooking."

"I would be amenable to apple pie, however."

"Mr. Spock, I think we're going to get along just fine."

Spock took out his comm and flipped it open. "Mr. Hendorff," he said, his lips twitching into a smile. "Two to beam up."

**Author's Note:**

> Thank you for reading! You can also find me [on Tumblr](http://museaway.tumblr.com) and [on Livejournal](http://museaway.livejournal.com).


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